The diagnosis of knee instability due to cruciate ligament injury requires a physical examination for clarity. Although MRI is now available, the scanning conditions of MRI often determine the accuracy of the results and are only informative for the diagnosis of the disease. Moreover, MRI provides the condition of the knee joint at rest, and the problem of joint loosening must be during movement. The patient’s questions boil down to three main ones: 1. whether conservative treatment is possible, including Chinese herbal medicine. 2. how effective the surgery will be and whether it will allow you to play sports as before. 3. the risk of anesthesia. These questions are difficult to answer until you have a confirmed diagnosis. For patients with cruciate ligament injuries: 1. The current gold standard of treatment is surgery under arthroscopy. This surgery is less invasive and has a faster recovery. It would be incorrect to say that the results after surgery are better than before the injury. The surgery is only a diligent ligament repair or reconstruction, and all current medical treatments do not allow patients to recover 100%. However, the purpose of surgery is to restore the athletic level for intense competition. Athletes who have had surgery can still win world championships. For example, Cristiano Ronaldo, who has done 3 times of cruciate ligament reconstruction, is still active on the green field.2. For cruciate ligament injury, there are two cases that can be treated without surgery. One is to reduce the amount of activity, such as the elderly or people who sit in the office for a long time without sports, they reduce the amount of exercise and increase muscle training will be able to meet their requirements. The issue of functional exercise is also a very important issue. Functional exercise is best performed with closed chain exercises, such as static squats. Swimming is fine, but breaststroke is not. Another type of patient who cannot have surgery in the short term, such as an athlete who does not need to have a major competition in the short term, can have surgery after 1 to 2 months by giving a temporary brace to immobilize and limit the knee movement. However, if a cruciate ligament rupture is not operated on or if surgery is delayed, joint laxity due to knee ligament damage can aggravate meniscal damage and cartilage wear, further aggravating the joint damage, often turning what could have been meniscal repair surgery into resection surgery and cartilage repair surgery into cartilage grafting. Therefore, once the diagnosis of cruciate ligament injury or joint instability is confirmed, early surgery should be performed.3. Anesthesia used to be a difficult hurdle in surgery, but currently anesthesia is developing rapidly. In the past, anesthetics with high side effects, such as ether, are no longer used in clinical practice, and the current anesthetics have fast metabolism and low side effects. The development of anesthesia technology and level can make patients worry less.